(a) Field of the Invention
The present invention relates to an improved structure of a ratchet wrench, and in particular, a ratchet wheel allowing a smooth teeth returning after application of the ratchet wrench.
(b) Description of the Prior Art
Conventional dual-direction ratchet wrench has been disclosed in U.S. Pat. No. 5,626,062, entitled xe2x80x9cSocket and Ratchet Wrench, Taiwan Publication No. 262785, entitled xe2x80x9cDriving Mechanism of a Hand toolxe2x80x9d, U.S. Pat. No. 5,230,262, entitled xe2x80x9cRatchet Wrenchxe2x80x9d, Taiwan application no. 88217482, Taiwan Publication No. 399509, entitled xe2x80x9cAn Improved Structure of a Direction Control Wrenchxe2x80x9d, Taiwan Patent Application No. 84201243, Publication No. 281946, entitled xe2x80x9cDriving Structure of a Hand toolxe2x80x9d, and Taiwan Patent Application No. 88212192, Taiwan Publication No. 386476, entitled xe2x80x9cAn Improved Structure of a Wrenchxe2x80x9d.
The structure of these conventional prior art has the following drawbacks:
As the wall of the ratchet wrench has no contact with the teeth member, and the ratchet wheel is restricted by the tightening member to provide free rotation, a tooth returning is achieved as the spring force at the rear section of the teeth member is overcome. However, if the tightening member is loosened to a certain extent, owing to a smaller resistance within the screw hole of the tightening element, i.e., there is no resistance to act against the ratchet wheel, if the resistance of the ratchet wheel is lesser than the elastic force at the rear section of the teeth member, teeth-retaining of the teeth member will not be occurred. Thus, in the case of clockwise or counterclockwise rotation of the ratchet wrench, the teeth member can drive the ratchet wheel to rotate the tightening member. This is the drawback of common ratchet wrench. If this happens, the ratchet wrench and the tightening member are separated so as to screw the tightening member manually. Accordingly, it is an object of the present invention to provide an improved structure of a ratchet wrench, which mitigates the above drawbacks.
Accordingly, it is an object of the present invention to provide an improved structure of a ratchet wrench, wherein the ratchet wrench provides a high torque dual-direction rotation function.
Yet another object of the present invention to provide an improved structure of a ratchet wrench having a plurality of engaging teeth on a teeth member and a ratchet wheel, characterized in that at least a cavity hole is appropriately provided on the engaging teeth and is mounted with an elastic body therein, thereby, when the teeth member is engaged with the ratchet wheel, the elastic body of the engaging teeth produces a small gap, by the elastic force of the elastic body, between the teeth member and the ratchet wheel, allowing a smooth teeth-returning between the teeth member and the ratchet wheel.
Other object and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawing.